JP6613766B2 - Liquid discharge head - Google Patents

Description

  The present invention relates to a liquid discharge head that discharges liquid.

  Patent Document 1 discloses a recording head of an ink jet printer having a configuration in which a plurality of head units (unit heads) are arranged in the width direction of a recording sheet as a liquid ejection head.

  The head of Patent Document 1 includes a circuit board (transmission board) that is electrically connected to the plurality of head units. The circuit board is erected and attached to a case that accommodates the plurality of head units. The plurality of head units are separately arranged on both sides of the circuit board in a direction orthogonal to the surface direction of the circuit board. From each head unit, a wiring member (flexible cable) extends toward the central circuit board, and the wiring member is connected to the circuit board at the tip.

  On both sides of the circuit board, two metal plates are respectively arranged with a gap between the circuit board. The rigidity of the entire head is enhanced by these two metal plates. For example, when the wiring member is thermocompression bonded to the circuit board, the deformation of the head due to heat can be suppressed.

JP 2014-184660 A

  In the head of Patent Document 1, since there is a gap between the circuit board and the metal plate, when the wiring member is pressed against the circuit board and connected, the circuit board may be bent to the opposite side of the wiring member. Conceivable. Due to the bending of the circuit board, the wiring member may not be sufficiently pressed against the circuit board, and connection failure may occur.

  An object of the present invention is to improve the reliability of electrical connection between a wiring member of each head unit and a circuit board in a liquid discharge head including a plurality of head units.

The liquid discharge head according to the present invention is divided into a circuit board disposed so that a surface direction thereof is along the first direction, and both sides of the circuit board in a second direction orthogonal to the surface direction of the circuit board. A main body having a plurality of head units that are arranged so that the positions in the first direction are shifted on both sides in the second direction, and a plurality of head units extending from the plurality of head units toward the circuit board; Wiring members, a plurality of contact portions provided on both side surfaces in the second direction of the circuit board in correspondence with the plurality of head units, to which the plurality of wiring members are respectively connected, and the circuit board Two support members respectively disposed along the circuit board on both sides in the second direction of
A first protrusion projecting toward the circuit board is provided at a portion of each support member that overlaps the contact portion located on the opposite side of the support member across the circuit board in the second direction. It is characterized by.

1 is a plan view of a printer 1 according to an embodiment of the present invention. 3 is a front view of the inkjet head 4. FIG. 2 is a plan view of the inkjet head 4. FIG. 2 is a perspective view of a part of the inkjet head 4. FIG. It is the VV sectional view taken on the line of FIG. FIG. 3 is a partially enlarged view of the inkjet head 4 showing the arrangement of the head unit 15. FIGS. 6A and 6B are cross-sectional views corresponding to FIG. 5 of the inkjet head 4 </ b> A according to a modified embodiment, where FIG.

  Next, an embodiment of the present invention will be described. The following is an example in which the present invention is applied to an inkjet printer that prints an image or the like by ejecting ink from a nozzle toward a recording sheet.

  In FIG. 1, the downstream side in the conveyance direction of the recording paper 100 is defined as the front side of the printer 1, and the upstream side in the conveyance direction is defined as the rear side of the printer 1. Further, the paper width direction orthogonal to the transport direction is defined as the left-right direction of the printer 1. The left side of FIG. 1 is the left side of the printer 1, and the right side of FIG. 1 is the right side of the printer 1. Further, a direction orthogonal to the conveyance surface of the recording paper 100 (a direction orthogonal to the paper surface of FIG. 1) is defined as the vertical direction of the printer 1. The front side in FIG. 1 is the upper side, and the other side in FIG. 1 is the lower side. Below, it demonstrates using each direction word of front, back, left, right, up and down suitably.

<Schematic configuration of printer>
As shown in FIGS. 1 and 2, the printer 1 includes a platen 3, four inkjet heads 4, two transport rollers 5 and 6, a control device 7, and the like housed in a housing 2. .

  A recording sheet 100 is placed on the upper surface of the platen 3. The four inkjet heads 4 (4c, 4m, 4y, 4k) are arranged side by side in the transport direction above the platen 3. The four inkjet heads 4 (4c, 4m, 4y, 4k) eject inks of four colors, cyan (C), magenta (M), yellow (Y), and black (K), respectively. Each inkjet head 4 is supplied with ink of a corresponding color from an ink tank (not shown). The inkjet head 4 is a so-called line-type head having a plurality of nozzles 16 (see FIG. 6) arranged in the paper width direction (left-right direction).

  The two transport rollers 5 and 6 are respectively arranged on the rear side (upstream side in the transport direction) and the front side (downstream side) with respect to the platen 3. The two transport rollers 5 and 6 are respectively driven by a motor (not shown) to transport the recording paper 100 on the platen 3 forward.

  The control device 7 includes a non-volatile memory such as a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), and an ASIC including various control circuits. (Application Specific Integrated Circuit). The control device 7 is connected to an external device 9 such as a PC so as to be able to perform data communication. The control device 7 controls each unit of the printer 1 based on print data sent from the external device 9.

  More specifically, the control device 7 controls the motors that drive the transport rollers 5 and 6 to cause the two transport rollers 5 and 6 to transport the recording paper 100 in the transport direction, and to move the four inkjet heads 4. Control is performed to eject ink toward the recording paper 100. As a result, an image is printed on the recording paper 100.

<Configuration of inkjet head>
Next, the configuration of the inkjet head 4 will be described in detail. Since the four inkjet heads 4 have the same structure, only one of the inkjet heads 4 will be described below. As shown in FIGS. 2 to 6, the inkjet head 4 includes a main body portion 10, a circuit board 11, a plurality of wiring members 12, and two support members 13 (13 </ b> A and 13 </ b> B).

(Main body)
The main body 10 includes a case member 14 and a plurality (nine) of head units 15 provided on the case member 14.

  The case member 14 is a member that is long in the left-right direction, which is the paper width direction. Nine head units 15 are attached to the lower part of the case member 14. As shown in FIGS. 3 and 6, the nine head units 15 are arranged in two rows along the left-right direction. Further, the position of the head unit 15 in the left-right direction is shifted between the two front and rear head unit 15 rows. That is, it can be said that the nine head units 15 are arranged in a staggered manner along the longitudinal direction of the case member 14. On the upper surface of the case member 14, passage holes 14 a through which a wiring member 12 described later passes are formed corresponding to the nine head units 15, respectively.

  Each head unit 15 has a rectangular planar shape that is long in the left-right direction. As shown in FIG. 6, a plurality of nozzles 16 arranged in two rows along the left-right direction are formed on the lower surface of each head unit 15. Although not shown, each head unit 15 includes a flow path member in which an ink flow path communicating with the nozzle 16 is formed, and an actuator that applies ejection energy to the ink flow path in the flow path member. The actuator is not limited to a specific configuration, but, for example, a piezoelectric actuator can be preferably used. When ejection energy is applied to the ink in the ink flow path by the actuator, ink droplets are ejected from the nozzles 16 communicating with the ink flow path.

(Circuit board)
The circuit board 11 is a rectangular board and is attached to the case member 14 of the main body 10 in a vertical posture in which the longitudinal direction is parallel to the left-right direction. The circuit board 11 extends upward from the case member 14 between the two rows of head units 15. In other words, as shown in FIG. 3, the nine head units 15 described above are arranged separately on both sides of the circuit board 11 in the front-rear direction perpendicular to the surface direction of the circuit board 11. ing. The circuit board 11 is connected to the control device 7 of the printer 1 by a flexible cable (not shown).

  Various circuit elements for controlling each head unit 15 are incorporated in the circuit board 11. As shown in FIG. 5, contact parts 17 corresponding to the head unit 15 are formed on both front and rear surfaces of the circuit board 11. More specifically, four contact portions 17 corresponding to the four head units 15 located on the front side of the circuit board 11 are provided at the center of the front surface of the circuit board 11 in the vertical direction. At the center of the rear surface of the circuit board 11 in the vertical direction, five contact points 17 corresponding to the five head units 15 located on the rear side of the circuit board 11 are provided. Depending on the arrangement of the head unit 15, the four contact portions 17 on the front surface of the circuit board 11 and the five contact portions 17 on the rear surface are displaced in the left-right direction.

  As shown in FIG. 5, for each of the front and rear surfaces of the circuit board 11, a ground wiring 18 is formed in a region overlapping the contact portion 17 on the opposite surface (a region on the back side of the contact portion 17). The ground wiring 18 does not need to be disposed on the back side of all the contact portions 17 of the circuit board 11, and may be disposed only on a region on the back side of some of the contact portions 17.

(Wiring member)
A plurality of wiring members 12 are connected to the plurality of head units 15, respectively. As shown in FIG. 5, the wiring member 12 is obtained by mounting a driving IC 20 on a film-like resin substrate 19 on which a large number of wirings are formed, and is called COF (Chip On Film). Each wiring member 12 extends upward from the head unit 15 through the passage hole 14 a of the case member 14. The leading end of the wiring member 12 is electrically connected to the contact portion 17 formed on the front and back side surfaces of the circuit board 11 by a conductive adhesive such as an anisotropic conductive film (ACF) or anisotropic conductive paste (ACP). Connected.

  As described above, the control device 7 of the printer 1 and the circuit board 11 are connected by the flexible cable. Further, the circuit board 11 and each head unit 15 are connected by the wiring member 12 on which the driving IC 20 is mounted. The circuit board 11 sends a signal for controlling the head unit 15 to the drive IC 20 of each wiring member 12 based on the signal sent from the control device 7. Each drive IC 20 outputs a drive signal for driving the actuator to the head unit 15 based on a signal from the circuit board 11.

(Support member)
The two support members 13 (13A, 13B) are both metal plates formed of aluminum or copper. The two support members 13 are arranged along the circuit board 11 on both front and rear sides of the circuit board 11. A lower end portion of each support member 13 is attached to the case member 14, and each support member 13 extends upward from the case member 14 in parallel with the circuit board 11.

  In the lower half portion of each support member 13, an opening 23 for exposing the contact portion 17 of the circuit board 11 from the support member 13 is formed. Four openings 23 corresponding to the four contact portions 17 on the front surface of the circuit board 11 are formed in the front support member 13A, and five contact points on the rear surface of the circuit board 11 are formed in the rear support member 13B. Five openings 23 corresponding to the portion 17 are formed. The width of each opening 23 in the left-right direction is larger than the width of the corresponding contact portion 17. In addition, the upper end position of each opening 23 is above the upper end position of the contact portion 17. Thereby, when viewed from the front-rear direction perpendicular to the surface direction of the circuit board 11, the corresponding contact portions 17 are arranged in the respective openings 23. The tip end portion of the wiring member 12 extending from the head unit 15 is connected to the contact portion 17 exposed at the opening 23.

  Here, the wiring member 12 is connected to the circuit board 11 with the conductive adhesive interposed between the leading end of the wiring member 12 and the circuit board 11. By thermocompression bonding to Here, since the support member 13 is disposed on the opposite side of the contact portion 17 across the circuit board 11, the circuit board 11 against which the wiring member 12 is pressed is supported by the support member 13 from the back side during the thermocompression bonding. It is done.

  In the present embodiment, since the support member 13 is a metal plate, a part of the transmitted heat can be radiated from the metal plate when the wiring member 12 is thermocompression bonded to the circuit board 11. The two support members 13 on both sides of the circuit board 11 also serve as an electromagnetic shield that covers the circuit board 11. In other words, electromagnetic waves (noise) from the outside are blocked by the metal support member 13, and the noise hardly reaches the circuit board 11.

  However, if the support member 13 is disposed with a gap between the circuit board 11 and the wiring member 12, the circuit board 11 is bent when the wiring member 12 is pressed, and the wiring member 12 is sufficiently pressed against the circuit board 11. There is a risk that poor connection will occur. However, if the support member 13 is disposed in close contact with the entire side surface of the circuit board 11, the wiring formed on the circuit board 11 comes into contact with the support member 13. In particular, when the support member 13 is a metal plate, the wirings on the circuit board 11 are short-circuited. Therefore, in the present embodiment, each support member 13 is formed with a convex portion (first convex portion 21 and second convex portion 22) that partially supports the circuit board 11.

(1) 1st convex part The 1st convex part which protruded to the circuit board 11 side in the part which overlaps with the contact part 17 located on the opposite side (back side) of the supporting member 13 of each supporting member 13 across the circuit board 11 21 is provided. In other words, the front support member 13 </ b> A is provided with five first convex portions 21 corresponding to the five contact portions 17 on the rear surface of the circuit board 11. In addition, four first convex portions 21 corresponding to the four contact portions 17 on the front surface of the circuit board 11 are provided on the rear support member 13B. The lengths of the first convex portion 21 in the up-down direction and the left-right direction are respectively larger than that of the contact point portion 17. Then, when viewed from the front-rear direction orthogonal to the surface direction of the circuit board 11, the contact portion 17 is disposed in the first convex portion 21. As shown in FIG. 2, the first protrusions 21 of the support members 13 are arranged alternately with the upper end of the opening 23 for exposing the contact portion 17 in the left-right direction. As shown in FIG. 5, the tip of each first convex portion 21 is in contact with the circuit board 11.

  The 1st convex part 21 is formed by the press drawing process with respect to the supporting member 13 which consists of metal plates. That is, when a portion of the support member 13 is locally squeezed, a portion of the support member 13 protrudes toward the circuit board 11 to form the first convex portion 21.

  With the above configuration, when the wiring member 12 is pressed against the contact portion 17 and connected, the circuit board 11 is supported from behind by the first convex portion 21 located on the back side of the contact portion 17. Further, since the first convex portion 21 is in contact with the circuit board 11, the circuit board 11 is reliably supported by the first convex portion 21. Thereby, the bending of the circuit board 11 is suppressed, and the wiring member 12 can be reliably pressed and connected to the contact portion 17.

  In addition, although the formation method of the 1st convex part 21 is not specifically limited, In this embodiment, the 1st convex part 21 is formed when a part of metal plate which comprises the supporting member 13 is restrict | squeezed locally. . In this structure, the 1st convex part 21 can be formed easily. Moreover, although it is also possible to attach another member, such as resin, to the support member 13 to form the first convex portion, the manufacturing cost can be suppressed as compared with such a case.

  In addition, as shown in FIG. 5, the ground wiring 18 is provided in a region overlapping with the contact portion 17 disposed on the opposite surface (region on the back side of the contact portion 17) for each of the front surface and the rear surface of the circuit board 11. Is formed. Therefore, the first convex portion 21 located on the opposite side of the contact portion 17 across the circuit board 11 comes into contact with the ground wiring 18. Thereby, since the metal support member 13 can be dropped to the ground, generation of static electricity can be prevented.

(2) Second convex portion As shown in FIGS. 4 and 5, the second convex portion 22 protruding to the circuit board 11 side is provided on the upper end portion of each support member 13 on the side opposite to the main body portion 10. It has been. That is, the second convex portion 22 is located above the contact portion 17 and the first convex portion 21. The second convex portion 22 is formed by bending the upper end portion of the support member 13 toward the circuit board 11, and extends over the entire length of the support member 13 in the left-right direction.

  Since each support member 13 is provided with a second convex portion 22 in addition to the first convex portion 21, the circuit board 11 is connected not only to the first convex portion 21 but also to the first convex portion 21 when the wiring member 12 is connected. It is supported also by the 2nd convex part 22 separated from the 1 convex part 21. FIG. Thereby, the bending deformation of the circuit board 11 is suppressed, and a better connection is possible. Note that if the protruding amount h1 of the first convex portion 21 and the protruding amount h2 of the second convex portion 22 are equal, the support member 13 is easily maintained in a substantially parallel state with respect to the circuit board 11, and therefore the circuit board 11 This is preferable from the viewpoint of suppressing the bending of the resin.

  Moreover, although the formation method of the 2nd convex part 22 is not specifically limited, In this embodiment, the 2nd convex part 22 is formed by the edge part of the supporting member 13 being bent. That is, the 2nd convex part 22 can be easily formed only by bending the upper end part of the supporting member 13 which consists of a metal plate. Further, the end portion of the support member 13 is bent, so that the rigidity of the support member 13 is increased and the support function of the circuit board 11 is improved.

  In addition, the rigidity of the support member 13 is further increased by the second convex portion 22 extending in the left-right direction (the longitudinal direction of the circuit board 11) at the upper end portion of the support member 13. In addition, a gap between the circuit board 11 and the support member 13 is closed by the second convex portion 22 extending in the left and right direction at the upper end portion of the support member 13. Thereby, the effect that the noise from the upper part is blocked reliably is also acquired.

  In the embodiment described above, the inkjet head 4 corresponds to the “liquid ejection head” of the present invention. The paper width direction corresponds to the “first direction” of the present invention. The transport direction corresponds to the “second direction” of the present invention. The vertical direction corresponds to the “third direction” of the present invention.

  Next, modified embodiments in which various modifications are made to the embodiment will be described. However, components having the same configuration as in the above embodiment are given the same reference numerals and description thereof is omitted as appropriate.

1] From the viewpoint of reliably preventing the circuit board 11 from being bent when the wiring member 12 is connected, it is preferable that the first convex portion 21 of the support member 13 located behind is in contact with the circuit board 11. However, in the area of the circuit board 11 where the first convex portion 21 is in contact, it becomes impossible to arrange the elements constituting the wiring and the circuit, so that the degree of freedom of arrangement of the wiring and the elements becomes low. From this viewpoint, each first convex portion 21 may be separated from the circuit board 11.

2] The amount of protrusion may be different between the plurality of first protrusions 21 of each support member 13. For example, the following points are considered as to which position the first convex portion 21 is to be raised.

  The ease with which the circuit board 11 bends when the wiring member 12 is pressed differs between the end portion in the longitudinal direction (left-right direction) and the center portion of the circuit board 11. Specifically, it is easy to bend at the center part and is difficult to bend at the end part. Therefore, if the first convex portion 21 located on the end side is arranged away from the circuit board 11, when the wiring member 12 is strongly pressed against the end of the circuit board 11, the circuit board 11 The circuit board 11 may be damaged before it is bent until it comes into contact with the first convex portion 21.

  Therefore, in the inkjet head 4A of FIG. 7, the protrusion amount ha of the first convex portion 21a located on the end side in the left-right direction among the plurality of first convex portions of each support member 13 is larger than that of the first convex portion 21a. Is larger than the protruding amount hb of the first convex portion 21b located on the center side. Since the protruding amount ha of the first convex portion 21a on the end side is large, when the wiring member 12 is pressed, the first convex portion 21a comes into contact with the circuit board 11 when the deflection of the circuit board 11 is small. Therefore, damage to the circuit board 11 is prevented. On the other hand, since the protruding amount hb of the first convex portion 21b on the center side is small, the first convex portion 21b can be separated from the circuit board 11 except when the wiring member 12 is pressed. Thereby, it becomes easy to arrange | position wiring 25 grade | etc., In the center part of the circuit board 11, and those arrangement | positioning freedom increases.

  Further, the first protruding portion 21a on the end side with a large protruding amount is in contact with the circuit board 11 (the ground wiring 18), and the first protruding portion 21b on the center side with a small protruding amount is separated from the circuit board 11. Is preferred. Since the first convex portion 21a on the end side is always in contact with the circuit board 11, the bending of the circuit board 11 when the wiring member 12 is connected can be reliably suppressed.

2] The first convex portion and the second convex portion are not limited to the form formed by press drawing or bending. For example, a 1st convex part and a 2nd convex part may be formed by making liquid resin adhere to a support member, and making it heat-solidify.

3] In the above embodiment, each support member 13 is provided with the second convex portion 22 in addition to the first convex portion 21 corresponding to the contact portion 17, but the second convex portion is not essential and is omitted. Is possible.

4] In the above embodiment, the support members 13 extend in the longitudinal direction of the circuit board 11 and are arranged one by one on the front side and the rear side of the circuit board 11, but are arranged separately for each head unit 17. May be. For example, in the arrangement of the head unit 15 as shown in FIG. 3, five support members are arranged on the front side of the circuit board 11 corresponding to the five rear head units 15, and the rear side of the circuit board 11. Alternatively, four support members may be arranged corresponding to the four head units 15 on the front side.

5] The material of the support member is not limited to a metal, and may be a non-metallic material. However, the support member is required to have a certain level of rigidity in order to support the circuit board. Therefore, it is preferably formed of a non-metallic material having high strength such as hard plastic.

4,4A Inkjet head 10 Main body 11 Circuit board 12 Wiring member 13 Support member 15 Head unit 16 Nozzle 21 First convex portion 22 Second convex portion

Claims (11)

A circuit board arranged so that its surface direction is along the first direction;
A plurality of the circuit boards arranged separately on both sides in a second direction orthogonal to the surface direction of the circuit board, and arranged so that positions in the first direction are shifted on both sides in the second direction. A main body having a head unit;
A plurality of wiring members extending from the plurality of head units toward the circuit board;
A plurality of contact portions provided on both sides of the circuit board in the second direction corresponding to the plurality of head units, to which the plurality of wiring members are respectively connected;
Two support members respectively disposed along the circuit board on both sides of the circuit board in the second direction;
A first protrusion protruding toward the circuit board is provided in a portion of each support member that overlaps the contact portion located on the opposite side of the support member across the circuit board in the second direction. A liquid discharge head characterized by the above.   The liquid ejection head according to claim 1, wherein the first convex portion is in contact with the circuit board. Each support member is provided with a plurality of the first protrusions arranged in the first direction according to the arrangement of the contact portions.
Of the plurality of first convex portions, the first convex portion located on the end side in the first direction protrudes compared to the first convex portion located on the center side of the first convex portion on the end side. The liquid discharge head according to claim 1, wherein the amount is large. 4. The liquid ejection head according to claim 3, wherein the first convex portion on the end side is in contact with the circuit board, and the first convex portion on the center side is separated from the circuit board. 5. The liquid discharge head according to claim 1, wherein the support member is a metal plate.   The liquid ejection head according to claim 5, wherein the first convex portion is formed by locally narrowing a part of a metal plate constituting the support member. A ground wiring is formed in a region overlapping with the contact portion arranged on the other surface of the one surface of the circuit board in the second direction,
7. The liquid ejection head according to claim 5, wherein the first convex portion of the support member facing the one surface of the circuit board is in contact with the ground wiring. 8. The circuit board and the two support members extend from the main body having the plurality of head units in a third direction orthogonal to the first direction and the second direction,
8. The second convex portion protruding to the circuit board side is formed at an end portion of the support member opposite to the main body portion in the third direction. The liquid discharge head described in 1.   9. The second convex portion is formed by bending an end portion of the support member opposite to the main body portion in the third direction to the circuit board side. Liquid discharge head.   10. The liquid ejection head according to claim 8, wherein a protrusion amount of the first protrusion is equal to a protrusion amount of the second protrusion.   The liquid ejection head according to claim 8, wherein the second convex portion extends over the entire length of the support member in the first direction.

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